/* -*- mode: C -*-  */
/* 
   IGraph library.
   Copyright (C) 2010-2012  Gabor Csardi <csardi.gabor@gmail.com>
   334 Harvard street, Cambridge, MA 02139 USA
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 
   02110-1301 USA

*/

#include "igraph_types_internal.h"
#include "igraph_memory.h"

void igraph_fixed_vectorlist_destroy(igraph_fixed_vectorlist_t *l) {
  long int i, n=igraph_vector_ptr_size(&l->v);
  for (i=0; i<n; i++) {
    igraph_vector_t *v=VECTOR(l->v)[i];
    if (v) { igraph_vector_destroy(v); }
  }
  igraph_vector_ptr_destroy(&l->v);
  igraph_free(l->vecs);
}

int igraph_fixed_vectorlist_convert(igraph_fixed_vectorlist_t *l,
				    const igraph_vector_t *from, 
				    long int size) {

  igraph_vector_t sizes;
  long int i, no=igraph_vector_size(from);

  l->vecs=igraph_Calloc(size, igraph_vector_t);
  if (!l->vecs) {
    IGRAPH_ERROR("Cannot merge attributes for simplify", 
		 IGRAPH_ENOMEM);
  }
  IGRAPH_FINALLY(igraph_free, l->vecs);
  IGRAPH_CHECK(igraph_vector_ptr_init(&l->v, size));
  IGRAPH_FINALLY(igraph_fixed_vectorlist_destroy, &l->v);
  IGRAPH_VECTOR_INIT_FINALLY(&sizes, size);

  for (i=0; i<no; i++) {
    long int to=(long int) VECTOR(*from)[i];
    if (to >= 0) { VECTOR(sizes)[to] += 1; }
  }
  for (i=0; i<size; i++) {
    igraph_vector_t *v=&(l->vecs[i]);
    IGRAPH_CHECK(igraph_vector_init(v, (long int) VECTOR(sizes)[i]));
    igraph_vector_clear(v);
    VECTOR(l->v)[i]=v;
  }
  for (i=0; i<no; i++) {
    long int to=(long int) VECTOR(*from)[i];
    if (to >= 0) { 
      igraph_vector_t *v=&(l->vecs[to]);
      igraph_vector_push_back(v, i);
    }
  }
    
  igraph_vector_destroy(&sizes);
  IGRAPH_FINALLY_CLEAN(3);
  
  return 0;
}
